Automatic check valve



May 19, 1931. I. D. SMITH AUTOMATIC CHECK VALVE Filed April 1'7,- 1930 2 Shuts-Sheet l I Invenlor fiat,

' A llorney Patented May 19, 1931' I messes IRA n. smasher nnsrminnmnxas Aurormrro CHECK VALVE i Application filed April 17,

The present invention relates to an automatic check valveparticularly.designed for 7 use in a natural gas line so as toshut oil the therethrough,

gas whenever thepressure ceases which oc-' 1 curs due to freezing and also other causes;

An important object of the invention resides in the provision of a'valve of this nature which is exceedingly simple in its'construction, inexpensive to manufacture trong and durable, thoroughly efficient and reliable in use and operation, and otherwisewell adapted to the purpose for which it is designed.

With the above and numerous other objects in view as Will appear asthe description proceeds, the invention resides in certain novel features of construction, and in the combination and arrangement of parts as will be hereinafter morefully described and claimed; i

In the drawings: I

Figure l is a side elevation of the valveembodying the features of my invention,

Figure 2 is a top plan view thereof, V

Figure 3 is a-longitudinal verticalsection Figure dis. a vertical transverse section taken substantially on the lineiHof Figure 3, and I V V Figure 5 is a vertical transverse section taken substantially on the line 55 of Figure 3. 7

Referring to the drawings in detail it will be seen that the numeral 5 denotes an elongated body having a longitudinally v extend- 1 ing bore 6 therein. VNumeral Q denotes a threaded inlet and numeral 8 denotesv a threaded outlet so that the gas pipe line may be connected with the valve I lnthe inlet end of the body there is formed a recess in communication with the'bore 6" and the inlet 7 having a slanting seat9 against which gravitates a flap" valve 10 mounted on a shaft 11 journalled in the up per portion of the body and terminating at its ends outside the body in cranks '12to which are secured rods 14 projecting in op-, I p I statement of the invention and the above def posite directions therefrom. v

These cranks 12 are extended in somewhat the same direction as the flap valve 10 to assist in its gravitation. A cap 16 is detach- 1930. s rial no. 445,017. w

ably secured at 17 on the body over the recess 8 and a gasket 18 is interposed between the body and the cap plate 16.

A recess 20is formed at the outlet end of the body across the bore 6 and has a vertical valveseat 21 remote fromthe outlet end against whichis adapted to swing aflap valve 22o n a shaft23journalled in the upper portion of the body 6 and being formed with dependingicranlts 2lat its endstowhich are attachedupstanding rods 25 having inturned fingers26.,, V V I Now by swinging down the rods 24 the in 'turned fingers 526' may beflengaged over the rods 2e thereby holding both flap valves in J an open position as the pressure of the gas tends to swing the flap "valve 22 to the position shown in Figure 1 causing the fingers 26 to bear down on the rodsl l and maintaining the flap valve 10 in an open position;

However should the pressure cease then the valve 22 will swing to a closed position releasing the. fingers 26 from the/rods 14 so that the flap valve 10 willgravitate down wardly toa closed position andof course then the gas is shut off even though, the pressure should comeup again. 7 V In this Way asphyxiation by lights going outiandthelike is eliminated. 7 It is thought that theconstruction, opera- It is preferable toprovide a cap plate 25 over the recess 20 and to be detachably held' r 25 andithe body. This cap plate on its under faceis cut awayas at 28 to accommodate the swinging movement of the valve 22 to an open position. r

The present embodiment of the invention has been disclosed in considerable detail merely for the purposes of exeinplification since in actual practice it attains the features if of advantage enumerated as desirable in the scription. I V l t will be apparent that changes in the de- 7 tails ofconstruction, and in the combination so 7 tion, utility and advantages ofthis invention 7 null be thoroughly understood without a more detailed description thereof.

and arrangement of parts may be resorted to without departing from the spirit or scope of the invention as hereinafter claimed or sacrificing any of its advantages.

Having thus described my invention, what I claim as new is:

1. A safety valve of the class described including a body having a bore extending therethrough with flat valves one of which closes in the direction of the flow thronghthe bore and the other closes in the opposite direction, and means on the second valve for en: gaging means on the first valve to hold the first valve open when the pressure of the flow is sufficient to swing the second valve to an open position.

2. A device of the class described comprising a body having: a bore therein, a recess at one end of the bore a recess at the other end of the borcythe first mentioned recess being formed with a slanting valve seat, a flap valve closable thereagainst, a shaft rockable in the body to which the flap valve is attached, the second recess having a vertical valve seat, a flap valvec'losahle thereagainst, a shaft to which the second flap valve is attached, said shaft having cranks, rods Xtending from the crank, the rods associated with the second flap valvehaving inturned fingers to engage the rods of the first mentioned flap valves.

In testimony whereof I afiix my signature.

IRA D. SMITH. 

